Machine for stitching buttonholes.



No. 830,496. PATEN-TED SEPTJI. 190s. 0,A.DAHL.'

- MAGBINE FOR STITGHING 'BUTTONHOLES,

APPLIOATION FILED JUL Y1, 1903.

2 SHEETS-SHEET 2.

/////////II///I II/I/I I ciw zesazam UNITED sTATEs PATENT oEEIoE;

CHARLES A. DAHL, OF BOSTON, MASSACHUSETTS, ASSIGNOR TO THE REEOEBUTTONHOLE MACHINE COMPANY, OF PORTLAND, MAINE,

AND BOSTON, MASSACHUSETTS.

Specification of Letters Patent.

Patented Sept. 11, 1906.

Application filed July 1, 1903. Serial No. 163,830.

To aZZ whom) it Wmty concern:

Be it known that I, OI-rARLEs A. DAHL, a citizen of the United States,residing at Boston, in the county of Suffolk and State of Massachusetts,have invented an Improvement in Machines for Stitching Buttonholes, ofwhich the following description, in connection with the accompanyindrawings, is a specification, like letters on t e drawings representinglike parts.

This invention, relating to sewing-machines for stitchin buttonholes,has for its object to provide this class of machine with means wherebythe extent of relative movement of the stitch-frame or parts carryingthe stitch,- forming mechanism and the work holder or clamp may bereadily varied in extent to provide for stitching buttonholes ofdifferent lengths.

In accordance with my invention I combine with the cam employed toimpart the relative movement referred to or the longitudinal to-and-fromovement to that one of the two members, either the stitch-frame orwork-holder, whichever is moved while making the overedge stitches forthe sides of the 'buttonholes means whereby the effective length orthrow of the cam may be changed to provide a longer or a shorterto-and-fro movement to the part to be moved.

I have illustrated my invention as applied to a sewing-machine such asrepresented in United States Patent No. 616,604, dated October 18, 1898,in which the stitch-forming mechanism is moved to and fro by a camduring the stitching of the side edges of the but tonhole and the workholder or clamp is anchored; but myinvention as to certain features maybe applied equally well to a machine wherein the stitch-frame isanchored and the work-holder or moved to and fro.

Figure 1 in side elevation represents in section a sufficient portion ofone form of a buttonhole-sewing machine of well-known construction towhich my improvement has been applied. Fig. 2 is an enlarged detail.Fig. 3 is a plan view of the parts shown in Fig. 2.

The bed BZ'pivoted at 2 on supports B secured to a bench, the legs Bdepending from the bed at its end opposite the pivot, the work holder orclamp d mounted on the bed, the stitch or traveling frame B, sustainpartcarrying it is a cooperating under needle E and clamp (1 and means foractuating the same for clamping and overstitchin the edge of abuttonhole and for cutting t hebuttonhole will be actuated as ent.

In the machine illustrated in the patent referred to a stud carried bythe bed-plate, which is stationary, enters the groove 13 of thefeed-wheel B, and as said wheel is rotated the stitch-frame is moved toand fro longitudinally, and a buttonhole of one and the same length willbe produced.

In accordance with this present invention, wherein provision is made forvarying the length of the buttonhole at will without removing or puttinginto the machine any parts and wherein I have chosen to retain the usualfeed-cam, I have added to'the machine means which I will now describefor the production of a buttonhole of any desired length.

Instead of the stationary stud held in the bedplate, as in the machinedescribed in said patent, I employ a lever at, having a stud (1.

provided for in said pat- (Shown in full lines, Fig. 3, and in dottedlines in Figs. 1 and 2.) The lever is pivoted on a stud-screw 0, held inthe lug h, and the stud a enters, as before, the cam-groove B. The levera has a segmental groove b, th t receives a guide-block (if, having acrank-pin (1, said block being preferably slotted, as shown at (1 theslot being entered by a clamp-screw e, by which to clamp the block andcrank-pin in adjusted position, as when .it is desired to maintain thecrank-pin more or less out of axial line with the stud a. The crank-pind is embraced, as shown, by an arm (i mounted on the stud 2.

It will be understood that the stitch-frame is the body or weight to bemoved, that the crank-pin d is the fulcrum for the lever a, and that theextent of movement of the stitchframe will depend upon the position ofthe crank-pin d with relation to the longitudinal center of the stud a.For instance, with the crank-pin d and stud a in axial alinement thestitch-frame during the rotation of the cam B will travel for a lengthjust equal to the throw of the cam. By placing the crank-pin above thestud a the travel of the stitch-frame will be increased, and thebuttonhole willbe lengthened more or less, that depending on the extentof movement of said stud, and by depressing the crank-pin to a pointbelow the stud a the travel of the stitch-frame may be less than thestroke of the cam B, and the buttonhole will be consequently shortened.

I believe that I am the first to provide a sewing-machine in which thestitch-frame or part carrying the stitch-forming mechanism and thework-holder have a relative movement with respect the one to the otherfor stitching a buttonhole with means carried by the moving part forvarying the length of said relative movement, and I also believe that inthat class of these machines in which the stitch-frame or part carryingthe stitchforming mechanism is the moving member I am the first toprovide means for varying the length of said movement without thesubstitution of cams.

I am aware that in buttonhole-sewing machines in which the work-holderor workclamp is moved with respect to the stitchforming mechanism it hasbeen customary to vary the length of the movement of said work-holder byadjusting means upon the fixed or non-moving part of the machine, and Iam also aware that in buttonhole-machines where the stitch-frame or partcarrying the stitch-forming mechanisms is the moving member it has beencommon to providefor various lengths of movement by the substitution ofcams of different sizes; but my present invention differs from either ofthese.

Having described my invention, what I claim as new, and desire to secureby Letters Patent, is

1. A buttonhole-sewing machine comprising a stitch-frame withstitch-forming mech anism mounted therein, a work holder or clamp, oneof said members being longitudinally movable with respect to the other,means comprising a cam mounted on said movable member and connectionsbetween said cam and said fixed member for giving said longitudinalmovement, means for ad justing the connections between said cam and saidfixed member whereby the length of said longitudinal movement may beadjusted and buttonholes of various lengths made.

2. A buttonhole-sewing machine comprising a stitch-frame withstitch-forming mechanism mounted therein, a work holder or clamp, one ofsaid members being longitudinally movable with respect to the other;means comprising a cam mounted on said movable member, a lever pivotedto said movable member and vibrated by said cam, and connections betweensaid lever and said fixed member for giving said longitudinal movement;means for adjusting said connections upon said lever whereby the lengthof said longitudinal movement may be ad usted and buttonholes of variouslengths made.

3. A buttonhole-sewing machine comprising a stitch-frame withstitch-forming mechanism mounted therein, a work holder or clamp, saidstitch-frame being longitudinally movable with respect to thework-holder, a cam mounted upon the stitch-frame, connections betweensaid cam and the work-holder whereby upon the rotation of the cam the'said longitudinal movement is secured, means for adjusting saidconnections between said cam and said work-holder, where' by the lengthof said longitudinal movement may be adjusted and buttonholes of variouslengths made.

4. A buttonhole-sewing machine comprising a stitch-frame withstitch-forming mechanism mounted therein, a work holder or clamp, saidstitch-frame being longitudinally movable with respect to thework-holder, a cam mounted upon the stitch-frame, a lever pivoted to thestitch-frame and vibrated by said cam, connections between said leverand said work-holder whereby said longitudinal movement is secured,means for adjusting said connections upon said lever whereby the lengthof said longitudinal movement may be adjusted and buttonholes of variouslengths made.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

CHARLES A. DAHL.

Witnesses Gno. W. GREGORY, EDITH M. STODDARD.

